- Solid Phase Synthesis of Biologically active Benzimidazole Derivatives Catalysed by CH3S03H-Si02 under Solvent free Condition
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A simple an expeditious method was established for the synthesis of 2-Substituted-1H-Benzimidazole derivatives at 90°C using o-phenylenediamine and different aldehydes. It has been found that a mixture of Methanesulphonic acid-Si02to be an effective catal
- Datta, Arup,Roy, Sanjay
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p. 537 - 543
(2020/07/23)
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- Vanadyl Acetylacetonate-Copper (II) Trifluoro Methane Sulfonate Catalyzed Eco-friendly Synthesis of Substituted Benzimidazoles in Aqueous Media
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Various substituted benzimidazoles have been successfully synthesized in aqueous medium by developing VO(acac)2–Cu(OTf)2 catalytic system. A green synthetic protocol has been created in presence of water and cetyltrimethyl ammonium bromide (CTAB) system in an organic solvent free condition. This chemoselective cyclocondensation cumoxidation process occurred in aqueous media. In this suitable method easily synthesized 2-Substituted benzimidazoles with good yields and no 1,2-disubstituted by-products were noticed. Excellent yields, environmentally benign and mild reaction condition, easy purification of the desired products are the main attractive features of this newly devised method.
- Halder, Samiran
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p. 687 - 694
(2020/11/25)
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- Method for preparing benzimidazole and quinazoline compounds by adopting supported nickel catalyst (by machine translation)
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The invention discloses a method for synthesizing benzimidazole and quinazoline compounds by oxidative coupling and dehydrogenation of a nitrogen-doped hierarchical porous biomass-based carbon material supported catalyst and a preparation method. The method comprises the following steps: adding o-phenylenediamine compound, alcohol, supported catalyst, toluene and potassium tert-butoxide as a solvent, carrying out reaction under 50~150 °C conditions, carrying out reaction 4~24 hours, cooling to room temperature, filtering the reaction liquid, and obtaining a benzimidazole compound or quinazoline compound. The method adopts "one-pot method" preparation, the intermediate can be separated and purified, energy consumption can be reduced, and the efficiency. (by machine translation)
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Paragraph 0054-0056; 0057; 0059; 0060
(2019/07/16)
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- Additive- and Oxidant-Free Expedient Synthesis of Benzimidazoles Catalyzed by Cobalt Nanocomposites on N-Doped Carbon
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A one-pot direct synthesis of a wide range of biologically active benzimidazoles through coupling of phenylenediamines and aldehydes catalyzed by a highly recyclable nonnoble cobalt nanocomposite was developed. A broad set of benzimidazoles can be efficiently synthesized in high yields and with good functional-group tolerance under additive- and oxidant-free mild conditions. The catalyst can be easily recycled for successive uses, and the process permits gram-scale syntheses of benzimidazoles.
- Wang, Zhaozhan,Song, Tao,Yang, Yong
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supporting information
p. 319 - 324
(2019/02/12)
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- An Efficient Synthesis of 2-Substituted Benzimidazoles via Photocatalytic Condensation of o-Phenylenediamines and Aldehydes
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A photocatalytic method has been developed for the efficient synthesis of functionalized benzimidazoles. This protocol involves photocatalytic condensation of o-phenylenediamines with various aldehydes using the Rose Bengal as photocatalyst. The method was found to be general and was successfully employed for accessing pharmaceutically important benzimidazoles by the condensation of aromatic, heteroaromatic and aliphatic aldehydes with o-phenylenediamines, in good-to-excellent yields. Notably, the method was found to be effective for the condensation of less reactive heterocyclic aldehydes with o-phenylenediamines.
- Kovvuri, Jeshma,Nagaraju, Burri,Kamal, Ahmed,Srivastava, Ajay K.
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supporting information
p. 644 - 650
(2016/10/21)
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- A Reusable Co Catalyst for the Selective Hydrogenation of Functionalized Nitroarenes and the Direct Synthesis of Imines and Benzimidazoles from Nitroarenes and Aldehydes
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The use of abundantly available transition metals in reactions that have been preferentially mediated by rare noble metals, for example, hydrogenations, is a desirable aim in catalysis and an attractive strategy for element conservation. The observation of novel selectivity patterns with such inexpensive metal catalysts is especially appealing. Herein, we report a novel, robust, and reusable cobalt catalyst that permits the selective hydrogenation of nitroarenes in the presence of highly hydrogenation-sensitive functional groups, as well as the direct synthesis of imines from nitroarenes and aldehydes or ketones in the presence of such substituents. Furthermore, we introduce the first base-metal-mediated direct synthesis of benzimidazoles from nitroarenes and aldehydes. Functional groups that are easy to hydrogenate are again well tolerated.
- Schwob, Tobias,Kempe, Rhett
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supporting information
p. 15175 - 15179
(2016/11/25)
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- Synthesis and diverse general oxidative cyclization catalysis of high-valent MoVIO2(HL) to ubiquitous heterocycles and their chiral analogues with high selectivity
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The first synthesis and diverse oxidative cyclization catalysis properties of high-valent MoVI-triazole are demonstrated towards highly selective construction of benzimidazoles, benzothiazoles, isoxazolines, isoxazoles and their chiral analogue
- Pramanik, Nabyendu,Sarkar, Satinath,Roy, Dipanwita,Debnath, Sudipto,Ghosh, Sukla,Khamarui, Saikat,Maiti, Dilip K.
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p. 101959 - 101964
(2015/12/08)
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- Synthesis of glycal-based chiral benzimidazoles by VO(acac) 2-CeCl3 combo catalyst and their self-aggregated nanostructured materials
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(Figure Presented) VO(acac)2-CeCl3 combo catalyst has been developed for chemoselective cyclocondensation cum oxidation under mild reaction conditions toward synthesis of a new class of optically pure compounds, 2-(2′-C-3′,4′,6′-tri-O-benzyl/methyl-glycal)-1H- benzimidazoles. It involves an operationally simple synthetic protocol efficient for the syntheses of a wide range of chiral benzimidazoles in high yields without formation of undesired 1,2-disubstituted and pseudoglycal byproducts. Vanadium(V) is found as active oxidant for the chemical processes which is investigated by UV absorption spectroscopy. Highly ordered one-dimensional low molecular mass organic nanostructured materials are fabricated by nanocrystallization of the chiral nanoscale building blocks. Theoretical calculation by the B3LYP/6-31G** level of theory of the glycal-based chiral benzimidazoles shows out of planar geometry of the 1H-anthra[1,2-d] imidazole-6,11-dione moiety, which is responsible for the strong self-aggregation to generate ultralong nanostructured materials. We have also found nice agreement between the theoretical results with the experimental observation in 2D-NOESY experiments. The photophysical property of the solid nanostructured materials is also reported. 2009 American Chemical Society.
- Maiti, Dilip K.,Halder, Samiran,Pandit, Palash,Chatterjee, Nirbhik,De Joarder, Dripta,Pramanik, Nabyendu,Saima, Yasmin,Patra, Amarendra,Maiti, Prabir K.
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supporting information; experimental part
p. 8086 - 8097
(2010/02/28)
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- A practical oxone - Mediated, high-throughput, solution-phase synthesis of benzimidazoles from 1,2-phenylenediamines and aldehydes and its application to preparative scale synthesis
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Addition of oxone to a mixture of a 1,2-phenylenediamine and an aldehyde in wet DMF at room temperature results in rapid formation of benzimidazoles under very mild conditions. The reaction is applicable to a wide range of substrates including aliphatic,
- Beaulieu, Pierre L.,Hache, Bruno,Von Moos, Elisabeth
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p. 1683 - 1692
(2007/10/03)
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- Synthesis of amidine and bis amidine percursors
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The reactions of substituted o-phenylene diamines, o-aminophenol, o-aminothiophenol, 3,4-diaminopyridine with p-cyanobenzaldehyde by refluxing in nitrobenzene gave corresponding benzimidazole, benzoxazole, benzthiazole and imidazopyridine derivatives Ia,b
- Singhal, Nidhi,Johar, Monika,Lown,Sondhi
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